You have a free afternoon and no plan. Say where you are setting off from, and leave with a circular walk that starts where you actually are.
Everyone else gives you driving directions to a trailhead car park. Here the loop begins at the railway station, the tram, the metro or the bus stop, and “take me back to the station” returns you there from anywhere on the route. Trains, trams and metros come first, because they run on Sundays.